The present invention relates to a pneumatic brake booster comprising a booster housing, which in an exemplary embodiment is subdivided into at least two chambers by at least one axially movable wall to which a pneumatic differential pressure can be applied, a control valve controlling the differential pressure and being arranged in a control housing, an operable input member, which is connected to a valve piston, an output member which applies a boosting force to a master cylinder, as well as an accommodating element, which accommodates a rubber-elastic reaction element and the output member abutting thereon in a radial direction, with the accommodating element being axially and radially supported on the control housing and being held in an axial direction by means of a holding element.
DE 39 04 641 A1 discloses a pneumatic brake booster of this type. In the prior art brake booster, a bowl-shaped accommodating element is provided to accommodate the reaction element and the output member, its bottom being axially supported on a frontal end of the control housing. In this arrangement, the reaction element in an axial direction partly bears against the accommodating element, partly against the control housing and partly against an input member. In accommodating elements of this type that accommodate reaction element and output member, the bowl-type configuration of the accommodating element with regard to the slot situation between accommodating element and control housing and between accommodating element and output member is disadvantageous, because the bowl-shaped accommodating element has two diameters, the dimensions of which must be adapted to the control housing, the reaction element and the output member. In order to take this fact into account, a precise and cost-intense manufacture of the accommodating element is required, or relatively large slots must be tolerated, which have negative effects on the lost travel of the brake booster and a slot extrusion of the reaction element, however. Further, the sophisticated assembly of the holding element, which additionally serves to guide the output member, is considered as needing improvement.